The present invention has a particular application to harvesting seed from native grasses and wild flowers in their native habitat. Many species of grasses and wild flowers native to the prairies are in danger of being lost due to exclusion from their native habitats due to the incursions of man. It is now being recognized that reseeding of areas previously taken for agricultural or other purposes, is desirable. In order to reseed such areas with native grasses and wild flowers, it is necessary to recover seeds from such species where they occur naturally. This may often be in rough terrain that is not amenable to normal harvesting methods. Further, many wild plant varieties are endangered species, and harvesting of seed should be undertaken in such a manner as to impact the plants and their habitat as little as possible.
A number of prior art devices exist which deal with various aspects of gathering seed from crops and other plants in the field.
Hall (U.S. Pat. Ser. No. 765,831) discloses a seed stripping apparatus comprising a farm implement having a rotary brush and a hopper. The rotary brush knocks the seed off the plants into a gathering area. In order to prevent the seed being lost, a rotary fan is mounted above and behind the rotary brush to cause a counter-current of air to force the floating seed down behind the rotary brush and into a seed box. Hall also discloses a single towing bar offset to one side of the rotary brush. A handle is provided to adjust the height of the rotary brush above the ground.
Otis (U.S. Pat. No. 1,587,349) discloses a rotary brush mechanism supported on the end of an arm. The arm's height may be pre-adjusted in fixed increments. A hopper consisting of a two member clamshell-like cowling encapsulates the rotary brush, and provides a downwardly presented throat into which seed bearing portions of plants being harvested protrude. The plants are acted upon by the brush and the air current it creates in order to remove the seed from the plant. The hopper members are spaced apart at the top to provide a vent for the air current. The angle of presentation of the throat is adjustable by movement of the hopper members relative to each other, in order to compensate for change in tilt angle with change in elevation of the arm.
Neilson (U.S. Pat. No. 2,412,002) discloses a rotary, or brush, mechanism located within a collecting box. The apparatus is mounted upon a two-wheeled trailer for towing behind a vehicle. The forward end of the box enclosing the rotary brush may be moved vertically to adjust the height of the brush. A hand operated lever is provided to raise and lower the mechanism. However, vertical adjustment also effects the "tilt" of the brush and hopper apparatus.
Armstrong (U.S. Pat. No. 2,658,321) discloses a towed seed harvester with adjustable height and angle mechanisms. A tow bar is attached to one side of the apparatus which is carried on an axle and wheels. A rotary brush knocks seeds into the rear hopper compartment which has a hinged lid on the top rear surface. The hinged lid is spaced apart from the rear wall to provide an air vent. The unit may be adjusted for vertical height and tilt angle by means of a tilt mechanism including a hand lever, movement of which adjusts the angle between the tow bar and the apparatus. Vertical height of the unit may also be adjusted by raising or lowering the apparatus relative to the axle. However, adjustment of vertical height is relatively difficult, requiring that the apparatus be independently raised or lowered on standards attached to the axle and held with bore holes in the standard aligned with bore holes in a member secured to the apparatus. Also adjustment of the height by raising or lowering the apparatus on its axle varies the ground clearance of the apparatus. Further, the tilt mechanism is relatively complex, including several elongated moving parts which may cause maintenance problems.
U.S. Pat. No. 3,073,098 to Farrar discloses an apparatus for harvesting caster beans which includes an air suctioning mechanism for harvesting beans and depositing them in a gathering mechanism.